The technical field to which the present invention pertains is means by which a computer graphics designer can select the color to be given to a specific part of a graphics display.
With state-of-the-art color monitors and graphics software, a graphics designer can choose from thousands or even millions of colors in creating a graphics display. This number of colors allows the designer tremendous versatility, but presents a problem not encountered with simpler systems in which only a small number of colors (e,g., eight) is available. A palette comprising only a few colors can be displayed along one edge of the screen on which the designer is composing the display, as is done, for example, in U.S. Pat. No. 4,232,311, issued Nov. 4, 1980 to Roi D. Agneta, for "Color Display Apparatus". This expedient is clearly not practical, however, with a palette of even a few dozen colors. Alternatively, the palette can be displayed on the entire screen, permitting use of a larger number of colors, but requiring the designer to select the color and enter the choice, then to inspect the scene with the selected color, and then to repeat the process as many times as may be necessary to obtain the desired effect. The designer cannot view the color in the scene while selecting the color. This method is cumbersome and time-consuming, the more so because, with a large palette, the designer often finds it necessary to try several colors before indentifying exactly the right one.
Anoher system uses a control to select the value of one color characteristic at a time, viz., hue, saturation or intensity, the characteristic to be varied being selected by means of an entry via a digital keyboard. This increases the number of colors the designer can choose from, assuming the editing machine's software is able to handle a large palette, but the designer still can only select a plane of colors from the so-called color solid at once rather than a single color, because only one characteristic can be varied at once.
It is therefore the principal object of the invention to provide a convenient, simple-to-use apparatus for selecting the color of an element of a computer graphics display.
Another object of the invention is to provide such an apparatus adapted to be connected to the monitor on which the display appears, or to a computer controlling the monitor, or both, in such a manner as to eliminate the necessity for the designer to enter the color choice via a keyboard.
Another object of the invention is to provide such an apparatus comprising an analog model of at least a portion of the so-called color solid, to enable the designer to select any color the monitor can display and not only one of a relatively small number of colors provided by the software developer.
Still another object of the invention is to provide such an apparatus capable of producing signals to control a monitor to change the displayed color continuously and substantially instantaneously.